Computer system crashes, grounding flights for hours and stranding thousands of passengers across nation

A key computer system used to run many daily operations at American Airlines failed Tuesday, forcing the nation’s third-largest carrier to ground all flights across the United States for several hours and stranding thousands of frustrated passengers on planes and at airports, including San Diego’s Lindbergh Field.

Flights already in the air were allowed to continue to their destinations, but planes on the ground from coast to coast could not take off. And travelers could do little to get back in the air until the computer system was restored.

American blamed its reservation system, which is used for much more than booking flights. Airlines commonly rely on such systems to track passengers and bags, monitor who has boarded a plane and to update flight schedules and gate assignments. The computers are also used to file flight plans and to help determine how much fuel to put in an aircraft or which seats should be filled to ensure a plane is properly balanced. The failure caused cascading delays and cancellations nationwide.

More than 780 American and its American Eagle offshoot flights were canceled all over the country, according to American Airlines spokeswoman Mary Frances Fagan. “Despite the magnitude of today’s disruption, we are pleased to report that we expect our operation to run normally with only a small number of flight cancellations expected tomorrow,” she said Tuesday.

There were six cancellations and 13 flights delayed at Lindbergh, airport spokeswoman Katie Jones said.

The systems were fixed by 1:30 p.m. Pacific time. But even as some flights took off, the airline expected delays and cancellations to continue for the rest of the day.

At airports, customers whose flights were canceled couldn’t rebook on a later flight. Passengers already at the airport were stuck in long lines or killed time in gate areas. They described frustration at the lack of information from airline employees.

Terry Anzur, a TV news consultant from Los Angeles who was stranded in Dallas-Fort Worth International Airport, said American Airlines gate employees were doing everything the old-fashioned, manual way because their computers were useless. “No one at the counter can do anything. They can’t check people in,” Anzur said.

To make amends, American offered to book people who needed to travel Tuesday on other airlines and pay for the fare difference. For those who wanted to delay their trips, American offered refunds or waivers from the usual fee for changing a reservation. But for several hours, the airline wasn’t able to process changes and refunds because of the computer failure.

American’s problems on Tuesday were reminiscent of what United Airlines passengers endured for several days last year. After merging with Continental, United experienced computer glitches in the combined reservation system. On one day in August, 580 United flights were delayed, and its website was shut down for two hours. Another outage in November delayed 636 flights. The problems prompted an apology from United Continental Holdings.

United’s technology glitches arose after a merger, but American’s headache occurred as parent AMR Corp. seeks government approval to merge with US Airways Group. A merger would let American leapfrog United and become the world’s biggest airline. The combined American-US Airways plans to use the American system that broke down Tuesday.